1. Field of the Invention
The present invention relates to an apparatus and method for obtaining depth information using an optical pattern, and more particularly, to a system for obtaining three-dimensional (3D) information such as depth information.
2. Description of the Related Art
Depth information or a depth value corresponds to information indicating a distance on a space. An image including depth information may be referred to as a depth image.
One of methods to obtain a depth image is an optical method. The optical method may be classified into a passive obtainment scheme and an active obtainment scheme.
The passive obtainment scheme is a scheme of obtaining an image from at least two viewpoints using a plurality of cameras. The active obtainment scheme is a scheme of projecting light onto a space and interpreting the projected light.
The passive obtainment scheme, which is also known as stereo vision technology, may obtain a depth image using two cameras, for example, both eyes of a human being, or a multi-view camera. When it is difficult to find a feature point at which a brightness value changes within a space of which distance is to be measured, the passive obtainment scheme may not accurately measure a distance.
The active obtainment scheme may not be significantly affected by illumination of a space or the presence or absence of a feature point, and may relatively accurately measure a distance. However, in the case of a visible light source that generally employs the active obtainment scheme, due to a dazzling phenomenon, it may be difficult to employ the active obtainment scheme when a person is present. Also, in a circumstance accompanied with a motion, the active obtainment scheme may be inappropriate to detect the motion by projecting a plurality of patterns.
Accordingly, a single pattern projection scheme using an infrared (IR) light source may be employed to overcome the above issue of the active obtainment scheme and to obtain 3D information.